Maybe write back an email to the third person (since you've got their adress in the forwarded email now, right?) and tell them not to come because this wasn't cleared with you and that you disagree with this behaviour.
Then the couple should apologize or be kicked out or at least arrange for a specific day that they will leave.
Thank you! The third party seems to be a nice (and polite!) girl, as far as I can tell (we hung out at a few mutual friends' dinner parties and such), so I think/hope she wouldn't say yes without consulting us first. (She actually gave up her place to go back to the US to campaign for Obama, so just for that I'm giving her the benefit of the doubt!)
I just talked to them about it and they avoided answering me directly (apparently the forwarding was a mistake (!!) and they just invited her to be "polite" and don't think she'll accept, and, oh, they're pretty sure they asked my bf about it and he said it'd be ok - a complete and utter lie). I'm so fed up with the whole thing, we decided we're gonna have a talk with them and ask them point blank to leave at the end of December, which IMO gives them more than enough time to find a place.
Maybe write back an email to the third person (since you've got their adress in the forwarded email now, right?) and tell them not to come because this wasn't cleared with you and that you disagree with this behaviour.
Then the couple should apologize or be kicked out or at least arrange for a specific day that they will leave.
I just talked to them about it and they avoided answering me directly (apparently the forwarding was a mistake (!!) and they just invited her to be "polite" and don't think she'll accept, and, oh, they're pretty sure they asked my bf about it and he said it'd be ok - a complete and utter lie). I'm so fed up with the whole thing, we decided we're gonna have a talk with them and ask them point blank to leave at the end of December, which IMO gives them more than enough time to find a place.